Crystal cutting device



Sept. 13, 1932. s H. STE|N 1,876,785

CRYSTAL CUTTING DEVICE Filed June l2. 1950 ff 1 l 1 I //6 l la* 5 f/ gri/EMM' 077706 @//7 2; 7 7

A TTORNE Y.

Patented Sept. 13,

UNITED 1 STATES vricrea sAMUEL n. s'rEIN, oEEnooKLYN, NEW YORK, AssIGNoE, BY MEsNE vAssrGNrifrn'Ni-rs,fro

riet IEA lGUILnEN, oF NEW YORK, N. Y.

cnYs'rAr. cU'rrrNG DEVICE Application led June"12,'1930. Serial No. 460,653.

This invention relates to a device for Acutf ting so-called unbreakable crystals to accurate size and shape of watch bezels and the formation wrist watches.

for fitting intothe seats more particularly for of fancy shaped vcrystalsv for The device of this' invention embodies improvements upon the crystal cutting apparatus of `Curt J. Rohland, filed December 24, 1928,

rlhe objects of the improve Serial No; 328,132;-

present invention are to upon the prior construction, so as to render the cutting of crystals from appropriate blanks more expeditiousxand accurate, to facilitate this operation and to render the apparatus susceptible Wrist watch bezels of all of cutting crystals for shapes and sizes.

With this in view, the present invention embodies numerous novel novel features consists of thechuck for holding features. One of these in so forming-the jaws the bezel that relatively high, as well'as yrelatively low orthin bezels can be properly held in place'the'rein'. Another feature ofthe inventionl consists ina novel formation the device which enab erse the contour of a of the guiding point of les it to properly travbezel even though the bezel seat is badly mutilated or broken away.

Another feature of in a novel forinof' cutter a blank broken therefrom will have ly scribe or cut the crystal when the-'invention consists adapted toV effectual in such away that smooth and clean "edges adapting it 4more readily to cooperate with the seat of the bezel.

@ther and addition al'features will be apparent from the followingdetaileddescription and the accompanying drawing and from the appended claim.

The accompanying drawing illustrates one practical embodiment yof .the invention, but

the construction therein shown is to be understood as illustrative, only,

and not as defining the limits of the invention.

Figure 1 is a plan view of a crystal cutting device embodying the Figure'2 isa side el Figures 3 and 4 are sections on 3-3 of Figure 2.

Figure 5 present invention. evation of such device. the line shows a novel follower-embodying this invention, partly in section andpartly in elevation.

Figure is an end view of said follower..v

a Figure 7 is a `central longitudinall section through anovel form of cutter embodying this'invention.

e .Referring'to the drawing, l'designatesthe frame of the device, the same being provided at one end with an uprightstandard 2: supporting a'spindle 3. .On one end of thegsp-indle is a blank holder 4 and theiother end a chuck 5 is mountediixedly ywithrespect to the holder 4, so that these parts are secured to one another against relative. rotation. Furthermore, the spindle is preferably supported in a standard 2 against rotation so that neither the chuck nor holder -are normally adapted to rotate. i The holder is provided with pins 5 adapted to support the blank to be cut in rigid position andin 'cen- -tered relation with respect The chuck 5 is of they self centeringitype and is provided with jaws 6 and 7. Thesejaws have opposed gripping faces and in accordance with this'invention, these gripping faces are stepped -or rabbeted as showntofprovide for two distinct gripping relations. F oreX- 'ample,'it will be noted from :theidrawing that said jaws are rabbeted as indicated yat 48 'tofprovide a seat 9 which is relatively shallow and that in addition to said'seat'there are the normal gripping faces-10. .Thus if it is desired togrip a relativelyV shallow or thin bezel said bezel may be engaged with vthe seats 9`as shown inFig. 3 wherein the bezel is designated by vInother words, inV this view the thin bezel is supported'in the rabbeted portionsfof the jaws, so thatfthe outerfface of the bezel will project beyond the outer faces of the jaws in 'order operate with the bezel seat without striking or engaging the jaws. vIfy it is desired to clamp a thick or high bezel this mayl be Yaccomplished as shown in Figure 4 by; engaging the bezel with the gripping faceslOas illustrated in this 'is vdesignated-10al With this arrangement, therefore, it is possible to properly support both thick and thin bezels in proper centered figure,'wherein the bezel '5 to the spindle. .Y

that the follower mayl properly `rcon ing jaws. This constitutes'ahighlyimp'ortant v advance because in the fitting' of crystals, bezels of widely diiiering sizes are continually required to be fitted and in the absence of such an arrangement as that illustrated a change in jaws would be essential for thin bezels.

Positioned at the rear end of the frame 1 are a pair of ears 11 supporting a pin 12 on which are pivoted a pair of links 13 `and the upper ends of these links carrywa pin 14,

On this pin is mounted a carrier 15 to thej opposite sides of which are pivotally connected a pair of arms 16 and 17. `These arms.n

Vuse of the head 31 are connected to the carrier in the following manner. The lateral edges of in the form of flat vertical faces and near the back ends vof each of these two vertical faces are -two semi-spherical depressions in whichare seated ball bearings 18. The inner faces of the arms bear against said vertical faces and are provided withregistering semi-spherical depressions into which the ball bearings also project. Screws 19 pass loosely through the carrier and are threaded into the arms 16 and 17 and rubber Vcushions 2O coact with thescrews to hold the inner faces of the arms yieldably againstthe outer lateral Vfaces of the carrier. The arms are provided with slots 21 which embrace the opposite ends of the pin 14, and while these slots permit a lateral separation of the free ends ofthe arms, they will maintain said arms at the same/transverse horizontal level.V The free ends of the arms 16 and 17 have finger pieces 22 whereby they may be grasped and manipulated. Saidarms are by kthis form of mounting .adapted to back and forth as well asV up and down movement and while their free ends may be'k laterally separated, they are normally forced together by the rubber cushions 20. f l

Mounted in perfect axial alinement on the two arms are a cutter 23 and a follower 24, the cutter being carried by the arm 16 and the yfollower-'by the arm 17. These parts are removably held in place by the set screws 25 and 26. The follower is shown in detail in Figure 5. It embodies a pin 27 which is clamped in place as stated. This pin is'of hollow tubular section, is closed at its outer end and flanged inwardly at its inner end to provide a constricted openingl28. f vExtending through the pin 27 is arod 29,

:the rear end of which is rigidly anchored as at 30, while the forward end projects through the opening 28 and carries a follower head 31.

.Extending coaxially beyond this head .31 is a follower point 32. This point'32 is adapted to coact with the crystal seat of the watch bezel, while the head 31 functions as a-fiange to bear against the outer face of the bezel.

By thus cooperating with the face of the bezel as the point 32 traverses the seat as will be understood, it will ybe apparent that if Vthe seat is uneven, broken away, or mutilated, the follower point will not slip off of thefseat,

ii-atl flange rvwould the Carrier.. are' but will be held in proper relation thereto by the flange or head 31, so as to permit of the fitting of a crystal to a badly mutilated seat. The head 31 may be of any appropriate shape, but is shown as substantially frusto conical. This shape has been Yfound to work with vhigh eiiiciency in cooperation with a wide variety of bezel contours and particularly to curved contours where a perfectly tend to produce an irregularity incutting.

iewed from a practical standpoint, the

acting as a stop to preclude thefollowing point 32 from disengagement with the seat is of considerable importance and solvesl the'problem which has has been a serious one in. crystal cutting machines. `Moreover, it solves this problem in asimple and eiiicient way and without materially adding tothe Vcost of the machine.

The follower. shown in Figures 5 and 6 is of the compensating type, the rod 29 being resilient and of a somewhat less diameter than the opening 28. In fact the diameter of therod 29 is preferably about one half of that ofthe opening 28. `Thus if the finger is forced laterally to engage with one side of said opening, itwill be apparent that the point32 will be tangent to the axis of the pin 27. j Ittherefore rfollows that if the point is engaged with the crystal seat of a watch bezel, the pointv of tangency between the follower point"'32 as well as thev axis of the cutter 23 are coaxial 'and ittherefore'follows that the cut or score line of such cutter will correspond exactlyto the corresponding point inthe bezel seat.v Accordingly absolute accuracy-in cutting ofthe crystal will result. 'I'wish it understood in connection with the follower that the employment of the follower point and follower head for the purposes stated is not limited to the compensating type of follower which I have described, but thatzitmay be associated with any type of follower without departing from this invention.

The cutter 23 which forms an important part'of this invention isshown in detail in Figure 7. f I t embodies a pin 33'into one end of which is fitted', by force fit or screw connection, afholder 34 and-in the outer end of this holder is gripped a diamond point 35. The diamond point may be secured to the holder in any suitable way, but this attachment is perfectly accomplished by spinning or burnishing as shown so that the diamond point is permanently and securely fastened to the vholder against' displacement. My experimentation and research in connection with cutters has shown that diamond points ordinarily employedv for cutting glass and similar materials are wholly inefficient in the cutting of non-breakable crystals from celluloidand similar substances used for these articles.

I have discovered in contradistinction that a conical shaped cutter operates with the highest efficiency and that there is an optimum apex angle which operates at the highest efficiency. This angle I have discovered to be 45 degrees. In other words, the cutter point 35 is in the form of a cone having a 45 degree angle at the apex. Such a cutter will efficiently score celluloid and similar material without too deep a cut and with a cut of suflicient depth to provide efficient breakage of the material along the line thus scored.

Furthermore, there is no tendency of such a cutter to tear or shred the material and such a cutter will be moreover maintained sharp indefinitely.

It will of course be understood that the cutting point 35 is positioned coaXially of the pin 33 and as stated this pin is maintained coaXially with respect to the follower 24, and it thus follows that when the follower is caused to traverse a bezel seat while the cutter is in engagement with the crystal blank held in the holder 4, said blank will be accurately scored to produce a crystal which will properly cooperate with a bezel s eat.

rIhe apparatus which I have described has been found in practice to be highly superior to any structure which has been heretofore eo suggested for the cutting of crystals for watch bezels. It is simple in construction, economical to manufacture and thoroughly eflicient in the performance of its intended f functions.

The drawing illustrates the invention in its preferred practical form, but the invention is to be understood as fully commensurate with the appended claim.

Having thus fully described the invention,

what I claim as new and desire to secure by Letters Patent is:

A watch crystal cutting device embodying means to support a watch bezel to be fittedV and a crystal blank in centered axial alinement and against relative movement with respect to one another, in combination with a crystal cutter, and a follower positioned in axial alinement with the crystal cutter, said follower comprising a head adapted to bear l on the face of the bezel adjacentV the crystal seat and having a follower point projecting from said head and adapted to engage with the seat of the bezel.

In testimony whereof I have signed the foregoing specification.

SAMUEL H. STEIN. 

